gio/gpollableinputstream.h

   1 /* GIO - GLib Input, Output and Streaming Library
   2  *
   3  * Copyright (C) 2010 Red Hat, Inc.
   4  *
   5  * This library is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU Lesser General Public
   7  * License as published by the Free Software Foundation; either
   8  * version 2 of the License, or (at your option) any later version.
   9  *
  10  * This library is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * Lesser General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU Lesser General
  16  * Public License along with this library; if not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 #ifndef __G_POLLABLE_INPUT_STREAM_H__
  20 #define __G_POLLABLE_INPUT_STREAM_H__
  21
  22 #if !defined (__GIO_GIO_H_INSIDE__) && !defined (GIO_COMPILATION)
  23 #error "Only <gio/gio.h> can be included directly."
  24 #endif
  25
  26 #include <gio/gio.h>
  27
  28 G_BEGIN_DECLS
  29
  30 #define G_TYPE_POLLABLE_INPUT_STREAM               (g_pollable_input_stream_get_type ())
  31 #define G_POLLABLE_INPUT_STREAM(obj)               (G_TYPE_CHECK_INSTANCE_CAST ((obj), G_TYPE_POLLABLE_INPUT_STREAM, GPollableInputStream))
  32 #define G_IS_POLLABLE_INPUT_STREAM(obj)            (G_TYPE_CHECK_INSTANCE_TYPE ((obj), G_TYPE_POLLABLE_INPUT_STREAM))
  33 #define G_POLLABLE_INPUT_STREAM_GET_INTERFACE(obj) (G_TYPE_INSTANCE_GET_INTERFACE ((obj), G_TYPE_POLLABLE_INPUT_STREAM, GPollableInputStreamInterface))
  34
  35 /**
  36  * GPollableInputStream:
  37  *
  38  * An interface for a #GInputStream that can be polled for readability.
  39  *
  40  * Since: 2.28
  41  */
  42 typedef struct _GPollableInputStreamInterface GPollableInputStreamInterface;
  43
  44 /**
  45  * GPollableInputStreamInterface:
  46  * @g_iface: The parent interface.
  47  * @can_poll: Checks if the #GPollableInputStream instance is actually pollable
  48  * @is_readable: Checks if the stream is readable
  49  * @create_source: Creates a #GSource to poll the stream
  50  * @read_nonblocking: Does a non-blocking read or returns
  51  *   %G_IO_ERROR_WOULD_BLOCK
  52  *
  53  * The interface for pollable input streams.
  54  *
  55  * The default implementation of @can_poll always returns %TRUE.
  56  *
  57  * The default implementation of @read_nonblocking calls
  58  * g_pollable_input_stream_is_readable(), and then calls
  59  * g_input_stream_read() if it returns %TRUE. This means you only need
  60  * to override it if it is possible that your @is_readable
  61  * implementation may return %TRUE when the stream is not actually
  62  * readable.
  63  *
  64  * Since: 2.28
  65  */
  66 struct _GPollableInputStreamInterface
  67 {
  68   GTypeInterface g_iface;
  69
  70   /* Virtual Table */
  71   gboolean     (*can_poll)         (GPollableInputStream  *stream);
  72
  73   gboolean     (*is_readable)      (GPollableInputStream  *stream);
  74   GSource *    (*create_source)    (GPollableInputStream  *stream,
  75                                     GCancellable          *cancellable);
  76   gssize       (*read_nonblocking) (GPollableInputStream  *stream,
  77                                     void                  *buffer,
  78                                     gsize                  count,
  79                                     GError               **error);
  80 };
  81
  82 GLIB_AVAILABLE_IN_ALL
  83 GType    g_pollable_input_stream_get_type         (void) G_GNUC_CONST;
  84
  85 GLIB_AVAILABLE_IN_ALL
  86 gboolean g_pollable_input_stream_can_poll         (GPollableInputStream  *stream);
  87
  88 GLIB_AVAILABLE_IN_ALL
  89 gboolean g_pollable_input_stream_is_readable      (GPollableInputStream  *stream);
  90 GLIB_AVAILABLE_IN_ALL
  91 GSource *g_pollable_input_stream_create_source    (GPollableInputStream  *stream,
  92                                                    GCancellable          *cancellable);
  93
  94 GLIB_AVAILABLE_IN_ALL
  95 gssize   g_pollable_input_stream_read_nonblocking (GPollableInputStream  *stream,
  96                                                    void                  *buffer,
  97                                                    gsize                  count,
  98                                                    GCancellable          *cancellable,
  99                                                    GError               **error);
 100
 101 G_END_DECLS
 102
 103
 104 #endif /* __G_POLLABLE_INPUT_STREAM_H__ */
 105